Topographical stereoscope



' Jan. 14, 1930. A. BARR ETAL TOPOGRAPHICAL STEREO SCOPE Filed NOV. 16. 1927 2 Sheets-Sheet l (C1! m dwmxd Jan. 14, 1930. A. BARR ET AL TOPOGRAPHICAL STEREOS'COPE 2 Sheets-Sheet 2 .Filed Nov. 16 1927 Patented Jan. 14, 1930 UNITED STATES PATENT OFFICE-1 r .ASdIGNORS 'I .O BARR A ND STBO'UD,

LIMITED, 01 GLASGOW, SCOTLAND 'roroemnroaz. sraanoscorn Applicat ion filed. November 16, 1927, Serial No. 283,590, and in Great Britain December 2, 1926a This invention relates to new or improved. means for examining stereoscopically a pair of photographs of a landscape or other scene, as seenfrom two stations some distance 5 apart, for eaanipla-for the examination of a pair of hotogra hs taken more or less vertically ownwar s from two positions of anv aeroplane, or of a pair of photographs taken more or less horizontally from two stations 10 near the ground.

According to this invention a topographical stereoscope comprises, two panels hinged together, the panels bein for receiving a pair of photographs whic are to be examined, frames carrying glass plates which lie over the photographs, the glass plate frames being hinged relatively to the panels, two

pairs of mirrors by means of which thephotographs placed on the panels may be viewe stereoscopically, frames for the mirrors connected together by linkages adapted to hold the mirrors in the correct positions relative to each other, and stay members adapted to hold the mirror systems in their correctpositions relatively to thebase members, the whole arran ement being such that it can be folded up into small space when not in use. v

An example of an instrument according to this invention will now be described with reference to the accompanying drawings, in which Figure 1 is a diagrammatic representation of the optical system.

Figure 2-is aview showing the right hand half of the instrument in front elevation and the left hand half in section.

Figure 3'is an end elevation.

1 Figure 4 is a view showing the right hand side of the instrument in plan and the left hand side of the instrument in plan with its mirror system removed- Figure 5 is a view showing the instrument partly collapsed.

Fi ure 6 1sv a view showing'the instrument comp etely folded up. a

The instrument illustrated comprises two panels A A to receive the two hotographs B B. When in use the panels A lie side by side, their surfaces extending as one some other set of marks,'those on t e two plane, and. for the purpose of description the ma be considered as resting flat on a tab e. he phenols are hinged together at 2, the axis of t e hinge 2 bein some distance above the surface plane of t e anels A A so that when the panels are fol ed by bein turned u parallel to each other there is en ficient dlstance between them to accommo date the folded other parts of the instrument. Above the panels there are frames G (L carrying glass plates D D the under. sides of plates 1) D being adapted to lie in contact with the photographs B B on the panels A A The glass plates D D have on their under sides a set of lines forming a id or.

plates corresponding to each other. The set of marks when seen stereoscopically will be referred to as the net. The. plates D D may be slidablein the frames C Q, enabling them to be moved nearer to or an ther from each other, so that the grids can be moved relatively .to the photographs The frames C G holding the plates D D. are hinged to the panels A and A conveniently on the same axis 2. At a convenient height above the panels A A (sa 6 inches 9r so) a pair of mirrors E E whlch will be referred to as the eye mirrors, are carried, set at an inclination of, say, 45 looking upwards and with their centres at about 1 inch from the vertical through the hinge axis 2. Outwardsfrdm the eye mirrors E E there is another pair of mirrors F E, which will be referred to as the object mirrors, roughly parallel to the eye mirrors E E- looking downwards and with their centres set at about the distance apart of the centres of the panels A. A. Thus, if the eyes of an observer aredirected downwards, see Figure 1, towards the eye mirrors E E photographs B B lyin on the panels A A are seen ster-= eoscopically superimposed on each other and the grids arealso seen superimposed upon each other and upon the photographs.

The arrangement illustrated shows two frames G G carrying the object mirrors F F and two frames J J carrying the eye mirrors E E. The upper .(and inner)edges of the frames J J are, hinged together at 3, 100

- tute a linkage of the hinge lying in the vertical plane throughfrthe hinge 2 and a little under the intersection'of the plates H parallel to the what may be called a facepiecefthe plates having holes through which the e es are directed downwards. Plates H 1 are hinged at 4 4 -to the frames J J near the hinge at 3. Frames G G fare hinaed to the plates H H at 6 6 Frames Gr are connected together at their inner (and up er) edges by the lates HHand parts of J. The lower e ge of each frame J J and its corresponding frame G Gr are kept at the proper distance apart by connecting rods K K. The frames G J with the plate H and connecting rod K see'Figure 2, constiarallelo am formso that these parts may lie folde u to occupy a small s ace as regards t ickness. The frames J, plate H and rod K are similar. A pair of frames L L, which may be called stay frames, are hinged together and to the panels A A at the axis 2 and lie directed outwards from each other. The position which they take up projecting upwardly from the panels may be controlled by projections'5 below the hinge, which projections are caughtby the inner edges of the panels A A when these are lying flat. The parts G H, (3: H are carried by thestay lanes of the frames J J.- Two l, parallel or approximately frames L L, being hinged thereto by hinIgIe pins 6 6 which also connect the plates H to the frames G G. The planes of the stay frames L L cut the frames J J near their outer. (lower) edges at 7 7 and at these places guides are provided, for example, pins ma be provided projecting-from the frames J J to slide in slots in the stay frames .L L lying radially from the axis 2. The upper (inner) edges of the frames G G may be connected to the lower (outer) edges of the frames J J by disconnectible connecting rods M M which when in place keep the systems of mirrors in their correct relative positions. The whole is so arranged that when the rods M M are released, the parts can be made to collapse into a small space practically in the plane of the stay frames L L and the whole is enclosed between the panels A A when these are hinged up into parallelism.

In use, a pair of photographic prints B B printed from negatives taken from the two ends of a base, are placed on the panels A A and moved into the correct relative attitudes and at such a distance apart that corresponding points on ,the two photo aphs can be .0'0- readily fused stereoscopical y. It is con- \venient to pin the centre points (principal 3 points) of the two photographslto sliders P which move in agIOOVGS along the centres of the panels A A, in line with each as other; the prints can then be rotated about panels A A constitutingtion and these pins andtransla'ted towards or from each other as may be r uired for easy fusing. The prints may t en be fastened to the panels, ay, clipped or pinned. If the panels A A are of metal, wooden insets N may be provided in the panels to take'the pins. I

The systems of markings, say grid lines on the undersides of the two glass plates being alike, when seen stereoscopically appear as a flat level net stretchedover the view. When the grid plates D towards or from each other, the net'appears to move towards or from the observer and its apparent distance may be made'to correspond to the apparent distance of an point on the landscape viewed. By thls means the relative distances of various objects in the landscape may be judged and the form and position of contour lines on the ground may be observed. When the direc- 1position of a contour line at any part of t e landsca e have been seen,'one of the grid plate fl ames, say C, with its grid plate D may be hinged up so that a pencil may be usedtolmark on the photoglra h the contour line referred-to. Scales 1 ma be rovided to indicate the position of t e grid plates 'D D in any setting with reference to their frames and therefore with reference to the photographs.

As has been stated, the instrument can also be used for examining two horizontal photographs and judging and more or less measuring by mea s of the grid plates the distances of various features in the landscape.

We claim 1. A topogra hical stereoscope comprising two picture ho ding panels hinged together for adjustment in either the same plane or into arallel planes, stay frames pivoted to the hlnged axis linkages ivoted to said stay frames near the top of the latter and hinged together in the vertical plane through the hingedaxis of theanels, object mirrors mounted on one side of the respective linka es and facing the res ctive panels, an eye mirrors mounte .on the opposite sides of the respective linkages and facing the. object mirrors.

eld' of. D are moved of the panels, parallel motionv 2. A topographical stereoscope comprising the top of the latter and hinged together in the vertical plane through the hinged axis of the panels, object mlrrorsmounted on one side of the respective linkages and facing the respective panels, and eye mirrors mounted on the opposite sides of the respective linkages and acing the object mirrors.

hinged together in t e vertical planethrough the hinged axis of the panels, object mirrors mounted on one side of therespective linkages and facing the respective panels, and eye mirrors mounted on the op osite sides of the respective linkages and acing the object mirrors. v

l. A. topographical stereoscope comprising two picture holding panels hinged together for adjustment in either the'same plane or into parallel planes, glass plates mounted in said panels, means'for adjusting said plates, toward and from the hinged axis of the 1 panels, stay frames pivoted to the hinged axis of the panels, parallel motion linkages pivoted to said stay frames near the top of the latter and hinged together in the verti cal plane through the hinged axis of the pane s, object mirrors mounted on one side of the reppective linkages vand facing the respective panels, and eye mirrors mounted on the opposite sides of the respective linkages and facing the object mirrors.

5. A topographical stereoscope comprising two picture holding panels hinged together for adjustment in either the same plane or into parallel planes, glassplates mounted in said panels, means for adjusting said plates towardand from the hinged axis of the panels,'stay frames pivoted to the hinged axis of the panels,'parallel motion linkages pivoted. to said stay frames near the top of the latter and hinged together in the vertical plane through the hinged axis, of the panels, object mirrors mounted on one side of the respective linkages and facing the respective panels, and eye mirrors mounted on theopposite sides of the respective link ages and facing the object mirrors, said plates having markings thereon for the purpose set fo d A topographical stereoscopecomprising two picture holding panels hinged together for adjustment in either the same plane or into parallel planes, stay frames pivoted to the hinged axis of the panels parallel motion linkages pivoted to sai stay frames near the top of the latter and hinged together in the vertical plane through the hinged axis of the panels, object mirrors mounted on one-side of the respective linkages and facing the respective panels, eye mirrors mounted on the. o posite sidesof the respective linkages and acing the object mirrors, and means for locking the stay frames in operative position;

7. A topographical stereoscope COI'IIPIlSlIlg be set angularly two panels .hinged together, the two panels being relatively movable angularly about the axis of the hinge for extension side by side, their surfaces extending as one plane, or for folding, their surfaces being substantially parallel to each other and at a distance apart,

larly whereby the mirrors may be set angularly for use or folded substantially parallel tov one another, the eye mirrors and the object mirrors with their frames being situated inthe angular spacethrough which the vpanels are movable and when folded containable betweenthe folded panels, for the purposes set forth.

8. A topographical stereoscope comprising two panels hinged together, the axis of the hinge being above the surface plane of the panels, the two panels being relatively movable angularly about the axis of the hinge for extension side by side, their surfaces extendingas one'plane, or for folding, their surfaces being substantially parallel to each other and at a distance apart, two glass plates, one for each panel, corresponding markings on the undersides of the plates, the glassplates being slidable nearer to or farther from each other, a pair of eye mirrors,

a pair of object mirrors, frames for the mirrors, frames for the glass plates, linkages for the frames of the mirrors, and stay frames extending from the panels for supporting the frames of the mirrors, said frames being movable angularl whereby the mirrors may for use or folded substantially parallel to one another, the eye mirrors and the object mirrors with their frames being situated in the angular space through which the anels are movable and when folded contamable between the folded panel's for the purposes set forth.

9. A. topographicalstereoscope comprising 'two panels hinged together, the 'axis ofthe hinge of the panels being above the surface plane of the panels,'the two panels being relatively movable angularly about the axis of the hinge for extension side by side, their surfaces extending as one plane, or for folding, their surfaces being substantially parallel to "each other and at a distance apart, two glass plates, one for each panel, corresponding markings on the undersides of the plate's,the glass plates being slidable nearer to or farther from each other, a pair of eye mirrors, a pair of object mirrors, frames for the mirrors, frames for the glass plates linkages for the frames of the-mirrors, an

ion 7 .frames being hinged hinge of the panels, said frames being movset angularly stay frames extending from the panels for supporting the frames of the mlrrors, the

frame for the glass plates and the stay a out the ans of the able .angularly whereby the mirrors may be parallel to one another, the eyemirrors and the object mirrors with'their frames being situated in the angular space through whic the panels are movable and when folded containable between the folded panels, for

the purposes set forth.

' ARCHIBALD BARR.

WILLIAM STROUD.

for use or folded substantially 

